refactor: rename marketplace to storefront across the entire monorepo

Comprehensive rename of all marketplace references to storefront:
- API module: apps/api/src/modules/marketplace/ → storefront/
- Components: MarketplaceHeader → StorefrontHeader, MarketplaceShell →
  StorefrontShell, MarketplaceFooter → StorefrontFooter
- Types: marketplace-homepage.ts → storefront-homepage.ts
- Test files: employee-marketplace-* → employee-storefront-*
- All source code identifiers, imports, route paths, and strings
- Documentation (docs/), CI config (.gitlab-ci.yml), scripts
- Dashboard, admin, storefront workspace references
- Prisma field names preserved (isListedOnMarketplace, marketplaceRating,
  marketplaceFunnelEvent) as they map to database schema

Validation:
- API type-check: 0 errors
- Storefront type-check: 0 errors
- Dashboard type-check: 0 errors
- Full monorepo type-check: only pre-existing admin TS18046

docs/project-design/PAGES.md

@@ -4,15 +4,15 @@ This document lists the pages that are actually present in the current frontend
 
 Source of truth:
 
-- `apps/marketplace/src/app`
+- `apps/storefront/src/app`
 - `apps/dashboard/src/app`
 - `apps/admin/src/app`
 
-## Marketplace App
+## Storefront App
 
 App:
 
-- `apps/marketplace`
+- `apps/storefront`
 
 ### Public routes
 
@@ -37,11 +37,11 @@ App:
 
 - `/` is the public marketing home.
 - `/pricing` consumes platform pricing from `/site/platform/pricing`.
-- `/explore` is the public marketplace search/discovery page.
-- `/explore/[slug]` is the company marketplace profile page.
+- `/explore` is the public storefront search/discovery page.
+- `/explore/[slug]` is the company storefront profile page.
 - `/review` is the review submission page driven by a reservation review token.
 
-### Not present in the current marketplace app
+### Not present in the current storefront app
 
 - `/about`
 - `/contact`
@@ -51,7 +51,7 @@ App:
 
 ### Renter routes present in code but not active product entrypoints
 
-These routes exist in the marketplace app:
+These routes exist in the storefront app:
 
 - `/renter/dashboard`
 - `/renter/notifications`
@@ -114,7 +114,7 @@ Base path:
 - `/dashboard` shows KPIs and booking-source analytics.
 - `/dashboard/fleet*` manages vehicles, maintenance, and calendar blocks.
 - `/dashboard/reservations*` manages the booking lifecycle and inspection workflows.
-- `/dashboard/online-reservations` handles public/marketplace booking intake.
+- `/dashboard/online-reservations` handles public/storefront booking intake.
 - `/dashboard/customers` is the company CRM view.
 - `/dashboard/offers` manages promotions.
 - `/dashboard/team` manages employees.
@@ -164,7 +164,7 @@ App:
 - `/dashboard/billing` manages platform billing operations.
 - `/dashboard/pricing` edits platform pricing, features, and promotions.
 - `/dashboard/notifications` inspects platform notifications.
-- `/dashboard/site-config` edits marketplace/site configuration content.
+- `/dashboard/site-config` edits storefront/site configuration content.
 
 ## Deliberately Not Listed